(a) Technical Field
The present description relates to a thin film transistor (TFT), and more particularly, to a TFT array panel and a manufacturing method of the same.
(b) Discussion of the Related Art
Liquid crystal displays (LCDs) are one of the most widely used flat panel displays. An LCD includes a liquid crystal (LC) layer interposed between two panels provided with field-generating electrodes. The LCD displays images by applying voltages to the field-generating electrodes to generate an electric field in the LC layer, which determines orientations of LC molecules in the LC layer to adjust polarization of incident light.
Commonly, LCDs include two panels respectively provided with field-generating electrodes, wherein one panel has a plurality of pixel electrodes in a matrix and the other has a common electrode covering the surface of the panel.
The LCD can display images by applying a different voltage to each pixel electrode. For this purpose, thin film transistors (TFTs), having three terminals to switch voltages applied to pixel electrodes, are connected to the pixel electrodes and gate lines. This configuration allows for the transmission of signals for controlling thin film transistors and allows for the data lines to transmit voltages applied to pixel electrodes formed on a thin film transistor (TFT) array panel.
The gate lines and data lines of the TFT array panel may include a conductive material having low resistivity such as, for example, aluminum (Al), an Al alloy, copper (Cu), a Cu alloy, silver (Ag) or a Ag alloy to reduce signal delay. However, the above low resistivity materials may have weak chemical or physical properties when they are used in a transistor so that the transistor may be ruined or an “on” current of the TFTs may be decreased, thereby degrading the image quality of an LCD.